A conveyance portion, a barrier portion, and a path are provided at places of a portion of a screw main body in which a kneading portion is provided. In at least one of the places, an entrance is opened to cause raw materials, conveyance of which is limited by a barrier portion to increase pressure on the raw materials, to flow in. The raw materials flowing in from the entrance flow through the path in the opposite direction to a conveyance direction of the conveyance portion. An exit is opened in an outer circumferential surface of the screw main body at a position outside the conveyance portion in which the entrance is opened.

The extruder includes: a cylinder having a first end portion and a second end portion respectively formed at two ends of the cylinder in an axial direction, and an ejection port formed in the first end portion; a screw including a shaft that is configured to rotate within the cylinder, and a screw blade that is provided on an outer circumferential surface of the shaft; a supplier that is attached to the second end portion side of the cylinder and is configured to supply a kneading target to an inside of the cylinder; and a plurality of protruding members that protrude from an inner wall surface of the cylinder.

A cylinder for a plastics-processing machine is provided, comprising at least two hollow-cylindrical bodies. At least one portion of at least one hollow-cylindrical body is provided with an inner coating, particularly a wear-protection layer, and can be attached to the other hollow-cylindrical body, the one hollow-cylindrical body being attachable to the other hollow-cylindrical body in a plurality of different positions. A device is further provided for processing a material and a method is also provided for operating an extruder.

A screw machine includes an inductive heating device for processing of material to be processed. The inductive heating device is used to heat the material in a heating zone. In the heating zone, at least one housing portion is made of an electromagnetically transparent material at least partly, the material being non-magnetic and electrically non-conductive, whereas at least one treatment element shaft is made of an electrically conductive material at least partly. The inductive heating device includes at least one coil formed integrally with a component of the at least one housing portion, in particular in such a way as to form a hybrid component. During the processing of the material, the inductive heating device generates an alternating magnetic field that produces eddy current losses in the at least one treatment element shaft, the eddy current losses leading to a temperature increase of the at least one treatment element shaft.

The extruder screw comprises a screw body (2) coated by an external functionalization coating (4), and also at least partially coated by a wear detection-quantification coating (5) arranged between the external surface (3) of the screw body (2) and the external functionalization coating (4), and detectable with respect to the external functionalization coating (4).

A barrel block for a twin-screw extruder constitutes a barrel including a cylinder and has joints at both ends. A first joint includes a first inner joint face on a peripheral edge of a first hole of an insertion hole for screws, and includes a first flank face and a first outer joint face on an outer periphery of the first inner joint face. The first outer joint face is located in the outer periphery of a plurality of first bolt holes. The first outer joint face is more recessed toward a second block end face than the first inner joint face.

A method of processing solid polymer particles of a poly condensate by a multi-rotation system. Polymer particles are melted in a first extruder section having an extruder screw that rotates. The partly molten polymer mass containing between 5% by volume and 50% by volume of unmolten polymer particles is passed into a second extruder section with a poly-rotation unit and multiple satellite screws that rotate therein. A diameter of the poly-rotation unit is increased compared to the screw diameter of the first extruder section and a transition cone is formed between the extruder sections and a conical gap is formed with respect to the housing. Ambient pressure plastification of the remaining polymer particles is performed by passage through a drive zone. The polymer mass is guided completely molten in the drive zone onward through a venting zone under reduced pressure.

The present invention relates to a method for the production of polyamide 6 with low extract content and a device for it. Here, a melt of non-extracted polyamide 6 is cleaned from monomer and oligomers in a degasification device in vacuum, wherein the vapor being withdrawn from the degasification device by the vacuum generation device is cleaned from monomer, oligomers and optionally water at first in a direct condenser which is operated with liquid ε-caprolactam and subsequently in a pre-separator which is cooled with a coolant, before it reaches the vacuum generation device. A particularly preferable variant of the method envisages the usage of the melt of polyamide 6 with low extract content so prepared in a direct process of spinning into textile fibers and/or filaments.

A screw extruder for extruding a kneaded material, includes: a pair of screws; a casing that houses the pair of screws and includes a supply port; and a roller-die. Each of the screws includes a shaft portion, and a spiral flight portion. The flight portion is formed into a shape in which a radial distance between the surface of the shaft portion and a tip of the flight portion decreases gradually toward a downstream end in an extrusion direction of a kneaded material. The casing has a tapered shape. Within a range between a downstream end of the supply port and a downstream end of the flight portion, a clearance between a top portion of the flight portion and an inner wall surface of the casing at the downstream end of the supply port is larger than a clearance at any other part.

A co-rotating self-cleaning two-screw extruder with a gradual number of threads and through self-cleaning function, and a processing method using the same, are disclosed. The screw assembly in the extruder includes a first screw (3) and a second screw (4) that co-rotate at the same speed in engagement; the first screw (3) includes a first single threaded element, a first transition element, a multiple threaded element, a second transition element and a second single threaded element that are connected in sequence; and the second screw (4) includes a first single threaded element, a third transition element, a multiple threaded element, a fourth transition element and a second single threaded element that are connected in sequence. The materials are transferred by rotation of the first (3) and second screws (4), and get their respective compositions mixed based on the structure of a gradual number of threads; with the flow passage expanded, contracted and re-expanded in shape in sequence, the materials undergo the single-to-multiple threaded, multiple-to-single threaded and again single-to-multiple threaded chaotic mixing in sequence; and the first and second screws achieve the self-cleaning effect by wiping each other.